Liquid Metal ‘Nano-Terminators’ Target Cancer Cells

The new cancer drug delivery system developed by the UNC School of Medicine and North Carolina State University improves efficacy of standard chemotherapy for ovarian cancer in mice with limited toxicity.

Researchers at North Carolina State University and the UNC School of Medicine have developed a new drug delivery technique that uses a biodegradable liquid metal to target cancer cells while limiting toxicity to normal cells. The development of this novel method, published in Nature Communications, may enhance the effectiveness of cancer drugs already in use and help doctors locate tumors.

“We can produce these molecules in bulk, and they appear to be wholly biodegradable with very low toxicity,” says Zhen Gu, PhD, senior author of aNature Communications paper and assistant professor in the joint biomedical engineering program at NC State and UNC. His team has developed other nano-sized drug delivery systems. “One of the advantages of this technique is that these liquid metal drug carriers – or ‘nano-terminators’ – are very easy to make,” he said.

To create the nano-terminators, researchers placed the bulk liquid metal (gallium indium alloy) into a solution that contained two types of molecules called polymeric ligands. The solution was then hit with ultrasound, which forced the liquid metal to burst into nanoscale droplets approximately 100 nanometers in diameter. The ligands in the solution attached to the surface of the droplets as they broke away from the bulk liquid metal. Meanwhile, an oxidized “skin” forms on the surface of the nanodroplets. The oxidized skin, together with the ligands, prevents the nanodroplets from fusing back together.

The anticancer drug doxorubicin (Dox) was then introduced into the solution. One of the ligands on the nanodroplet sucked up the Dox and held on to it. These drug-laden nanodroplets could then be separated from the solution and introduced into the bloodstream.